Bellows seal with groove edge folded over bead, for ball and socket joints

ABSTRACT

In a ball and socket joint comprising a ball and a socket in mutual swivelling sliding engagement with each other, the ball having a stud integrally formed at one end thereof and projecting outwardly through one end of the socket, the improvement consisting in forming the socket with an annular groove circularly disposed at the edge of the open end of the socket for fitting and retaining therein the beaded end of a flexible oil-resistant seal having a bellows type body provided at one end with an annular band stretched over the periphery of the stud.

This is a division of application Ser. No. 337,665 filed Jan. 7, l982,now U.S. Pat. No. 4,448,562.

BACKGROUND OF THE INVENTION

The present invention relates to a bellows seal for a ball and socketjoint having improved means for sealing the same against entrance offoreign matter.

Ball and socket joints generally consist of a stud terminating in a ballmember disposed in swivelling slidable engagement within a socket memberhaving a concave spherical segment conforming to that of the ball. Balland socket joints are commonly used in motor vehicle steering tie rodassemblies, in drag links, torque rods and like structures which, inservice, are exposed to dust, dirty water splashes, mud and otherforeign matter, and the joints are often provided with seals preventingentrance of foreign matter in the assembly. Bellows seals are generallyused for preventing entrance of foreign matter between the bearingsurfaces at the end of the socket from which a mounting stud projects,the mounting stud being welded to or formed integrally with a ballmember having a partially spherical surface in the socket member. Thebellows seals are made of flexible material, such as rubberized canvas,thin natural rubber or preferably synthetic rubber, neoprene, urethaneand the like, an end of the bellows being disposed in tight engagementwith a portion of the peripheral surface of the stud member, and theother end of the bellows being attached to the socket. Adhesive, gartersprings, elastic O-rings, circular clamps and other fastening means havebeen used in the past for attaching bellows seals to socket members, butit has been found that most bellows seals become detached from thesocket member during use in the field due to failure of the fasteningmeans, often long before the bellows portion of the seal hasdeteriorated beyond normal usefulness.

SUMMARY OF THE INVENTION

The present invention remedies the shortcomings of prior art bellowsseals by providing, in combination with a ball and socket joint whichhas an annular groove disposed around the exterior periphery of thesocket for retaining the corresponding end of the bellows in place atthe edge of the socket, a bellows seal having a reinforcing bead at theedge of the bellows fitted within the groove, and at least one edge ofthe groove folded over the bead.

Because of its excellent retention the bellows seal attachmentarrangement of the invention is particularly useful for heavy dutyapplications, such as truck or tractor tie rods, drag links, torque rodsand the like. In addition, the present invention provides a bellows sealfor a swivel joint which is able to handle relatively large amounts ofangular displacement between the joined elements.

Other objects and advantages of the present invention will becomeapparent to those skilled in the art when the following description ofthe best modes contemplated for practicing the invention is read inconjunction with the accompanying drawings wherein like numerals referto like or equivalent parts and in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, with portions in section, of a swiveljoint provided with a bellows seal fitted thereto according to thepresent invention, prior to final assembly;

FIG. 2 is a view similar to FIG. 1 but showing the structure after finalassembly; and

FIG. 3 is an enlarged view of a portion thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings in greater detail, the example of structureshown therein for a knuckle or swivel joint 10 is, for example, thatdisclosed generally in copending application Ser. No. 251,254, now U.S.Pat. No. 4,415,291, assigned to the same assignee as the presentapplication. The knuckle or swivel joint 10 which, per se, forms no partof the present invention, consists of a cold-headed half ball 13 havinga stud 12 integrally formed at one end thereof projecting from a socketin which the half ball 13 is disposed. The socket 14 has an integrallyformed shank 16 projecting from the outside surface of the socket.

The socket 14, in the example of structure illustrated, has an open end17, through which the stud 12 projects, which is provided at its edgewith an annular groove 18 circularly disposed around its exteriorperiphery and within which is fitted an annular bead 20, preferablytoroidal, that is substantially circular in section, which is formedintegrally at the end edge of a flexible oil-resistant bellows seal 22.The bellows seal 22 has, at its other end edge, an annular garter flange24 which is stretched around the periphery of the stud 12. The bellowsseal 22 has a flexible bellows-type pleated tubular body extendingbetween the end annular bead 20 and the end annular garter flange 24 sothat, while its ends remain fast, it can be considerably twisted,stretched and compressed without injury thereto.

The annular groove 18 is made in the usual fashion by machining the edgeof the open end 17 of the socket 14, or by forging, for example.

The bellows seal 22 is installed by disposing the bellows seal over thestud 12, with the edge end of the bellows seal provided with theintegral edge annular bead 20 directed toward the annular groove 18circularly disposed in the exterior periphery of the socket 14. Theannular garter flange 24 at the end edge of the bellows seal pleatedbody being elastically stretchable, the inner surface 26 of the sealannular garter flange 24 firmly engages the peripheral surface of thestud 12. The other end of the bellows seal pleated body 22 provided withthe integral annular bead 20 is fitted within the annular groove 18. Asshown particularly at FIGS. 2 and 3, if desired the exterior wall 27 ofthe annular groove 18 after insertion of the bellows seal bead 20 withinthe groove 18, is bent over as shown at 28, with the result that thebellows seal annular bead 20 is partially encased within the annulargroove 18.

It will be obvious to those skilled in the art that the groove 18 ispreferably only partially closed at its top so that the bellows seal canbe removed from the socket 14 if necessary for repacking the joint withlubricant or for replacing a damaged bellows seal. One method of foldingor bending over a wall of the groove 18 at the end of the manufacturingprocess is by way of a swaging die. The swaging die alters the shape ofthe exterior wall 27 of the groove 18 from that shown in dotted line atFIG. 3 to that shown in full lines at 28.

The bellows seal 22 is made of a convenient elastomeric, or elastic andstretchable material, preferably of molded neoprene or urethane having arelatively thin wall, and the interior of the bellows seal 22 may beadvantageously pre-packed with grease.

It will be appreciated that the bellows seal anchoring means of theinvention has useful applications to structures other than the specificball and socket joint structure illustrated and disclosed herein.

It will thus be seen that there has been provided by the presentinvention an improvement in bellows seals anchoring means for ball andsocket joints, for example, in which the object hereinabove set forth,together with many other practical advantages, has been successfullyachieved. While a preferred embodiment of the present invention has beenshown and described, it is to be understood that variations and changesmay be resorted to without departing from the spirit of the presentinvention as defined in the appended claims.

I claim:
 1. A method of sealing a junction between an elongated memberand a housing from which the elongated member projects and relative towhich the elongated member swivels, said method comprising providingsaid housing from which the elongated member projects and swivels withan annular groove disposed around the exterior periphery of the housing,disposing a resilient open-ended tubular member around said elongatedmember such that an open end of said tubular member is stretched aroundsaid elongated member, providing the other open end of said tubularmember with an integral reinforcing bead, fitting said integralreinforcing bead within said groove, and folding at least one edge ofsaid groove over said integral reinforcing bead.
 2. The method of claim1 further comprising forming said tubular member as a bellows.
 3. Amethod for sealing a ball and socket joint comprising a ball and asocket in mutual swivelling sliding engagement, said ball having a studintegrally formed therewith projecting outwardly through one end of saidsocket, said method comprising forming said socket at one end with anannular groove disposed around the exterior periphery of the socket,disposing a resilient tubular body around said stud, said resilienttubular body having an open end stretched around said stud and anotheropen end provided with an integral reinforcing bead, fitting saidintegral reinforcing bead within said annular groove, and folding atleast one edge of said groove over said integral reinforcing bead. 4.The method of claim 3 wherein said reinforcing bead is substantiallytoroidal.
 5. The method of claim 3 wherein said tubular member is formedas a bellows.